Obama, unlike liberal interventionists, is an admirer of the foreign-policy realism of President George H. W. Bush and, in particular, of Bush’s national-security adviser, Brent Scowcroft (‘I love that guy,’ Obama once told me). Bush and Scowcroft removed Saddam Hussein’s army from Kuwait in 1991, and they deftly managed the disintegration of the Soviet Union; Scowcroft also, on Bush’s behalf, toasted the leaders of China shortly after the slaughter in Tiananmen Square. As Obama was writing his campaign manifesto, The Audacity of Hope, in 2006, Susan Rice, then an informal adviser, felt it necessary to remind him to include at least one line of praise for the foreign policy of President Bill Clinton, to partially balance the praise he showered on Bush and Scowcroft. ...

Those who speak with Obama about jihadist thought say that he possesses a no-illusions understanding of the forces that drive apocalyptic violence among radical Muslims, but he has been careful about articulating that publicly, out of concern that he will exacerbate anti-Muslim xenophobia. He has a tragic realist’s understanding of sin, cowardice, and corruption, and a Hobbesian appreciation of how fear shapes human behavior. And yet he consistently, and with apparent sincerity, professes optimism that the world is bending toward justice. He is, in a way, a Hobbesian optimist.